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Esterel 45

Man & Speed game !

Since some months I was thinking about a New Model to be competitive in terms of speed against the ones sitting in the range of 39 and 50 Inches of length.
In my opinion, this development may be satisfied since many technologies has changed in the recent years and Rules did not changed very much to stay with the modern times !

I do recall the progress in the Digital Servos, Batteries, Keel construction techniques, and more recently the 3D Printing.
How long we shall ignore them ?

Old models developed in the 1930 and in 1988 are now out of date from technological point of view in spite of their excellent spread at International level.

My new model is called ESTEREL-45 and long 114.5 cm.

I have prepared a short PDF file describing the reasons behind this Design approach.

Re: Esterel 45

Often the time bring better solutions to an existing design project.
During my forced "rest time" I reviewed the Esterel 45 project.
Based upon the fact that, all the rest being equal, the lightest boat should be the faster.
The technology evolved and what was initially considered 4300g a good displacement, with more careful construction considerations, I found out that this limit can be lowered toward 3800g.
Of course not all parts are yet constructed, but I can anticipate that the major contributors to a potential weight reduction are the Servos and Fin and to a certain extent also to the Rig and as well the Hull and Deck material choice.
The recent class M "1290" construction proved that the Multi Chine shape generated a very strong hull.
There, I did used 3 coats of fiberglass of 80g/mē. Today I would use only 2 layers.
In 2001 my "Studio 2", a class M, was made with Carbon and Kevlar layers and weighted only 147g ! Probably it would not supported a lateral shock !
Considering that the Esterel 45" make use of only one Chine, but it is a smaller Hull than a M, I could make use of a stronger tissue than glass by using 93g/mē Carbon tissue combined with 68g/mē Kevlar or Carbon/ Kevlar.
The truth will be pop up once the model will be made. Noting that the shorter LWL will allow some margin of error before reaching the LOA.
Here below the actual Budget

Re: Esterel 45

Here below my last design trial aiming to total weight reduction. From 4300g down to 3800g/3850g and Sail Area of 73dmē
Not an easy model make to reach the design weight unless Carbon Tissue is used.
Many internal supports are based upon Carbon square tubes available with 4x4, 6x6, 8x8 mm
Some Options are supposed to increase weights.
Preferred solution Flat Deck with booms as close as possible to deck
Under consideration a 3 servos configuration: Main, Jib and Jib Trimmer/Backstay

Re: Esterel 45

This model being independent from known Class Rules, can be optionally equipped with 3 servos. Here a typical circuit example of a Jib Trimmer. Similar circuit could deal with the Backstay. 2-3kgcm servo is retained. Weight about 15g. The optional Jib trimmer servo is installed under the Deck. Additional servo functions may jeopardize the overall Displacement of 3800-3850g

Re: Esterel 45

A complete Servos and Supports setting is drawn. Modifications not excluded during construction to reduce weight overall. The hatch cover is still under design. Most supports are carbon square tubes 6x6 mm and 8x8 mm. For balance reasons the Jib trimmer servo is shifted right to let more space for Battery and Receiver. The Rudder Servo is external mounted on Deck.

Re: Esterel 45

Revised Flection strength W calculation of Carbon Tubes and Fin profile design. Using 4x4mm square carbon tubes + carbon sheet lamination it is possible to obtain a 6.5% profile. Leading edge with carbon sheet shaped and trailing edge with aluminum sheet for sharp shaping like a knife for better efficiency. Not sure about the number of square tubes, 2 or 3, most depend from each single strength. Ordered but not received yet. Use of 6x6mm square tube, while offering similar strength, is abandoned since Fin profile over 8% Rectangular Fin form 460mm (540) x 80mm constant profile.